gomoljson

README

gomol-json

gomol-json is a logger for gomol to support logging JSON over a network.

Installation

To install gomol-json, simply go get it and import it into your project:

go get github.com/aphistic/gomol-json
...
import "github.com/aphistic/gomol-json"

Examples

For brevity a lot of error checking has been omitted, be sure you do your checks!

This is a super basic example of adding a JSON logger to gomol and then logging a few messages:

package main

import (
	"github.com/aphistic/gomol"
)

// Create a new JSON logger, add it to gomol and log a few messages
func Example() {
	// Add a JSON Logger
	jsonCfg := NewJSONLoggerConfig("tcp://10.10.10.10:1234")
	jsonLogger, _ := NewJSONLogger(jsonCfg)
	gomol.AddLogger(jsonLogger)

	// Set some global attrs that will be added to all
	// messages automatically
	gomol.SetAttr("facility", "gomol.example")
	gomol.SetAttr("another_attr", 1234)

	// Initialize the loggers
	gomol.InitLoggers()
	defer gomol.ShutdownLoggers()

	// Log some debug messages with message-level attrs
	// that will be sent only with that message
	for idx := 1; idx <= 10; idx++ {
		gomol.Dbgm(
			gomol.NewAttrs().
				SetAttr("msg_attr1", 4321),
			"Test message %v", idx)
	}
}

Documentation

Overview

Package gomoljson is a JSON logger implementation for gomol.

Message order is not guaranteed during reconnection scenarios.

Example

Create a new JSON logger, add it to gomol and log a few messages

// Add a JSON Logger
jsonCfg := NewJSONLoggerConfig("tcp://10.10.10.10:1234")
jsonLogger, _ := NewJSONLogger(jsonCfg)
gomol.AddLogger(jsonLogger)

// Set some global attrs that will be added to all
// messages automatically
gomol.SetAttr("facility", "gomol.example")
gomol.SetAttr("another_attr", 1234)

// Initialize the loggers
gomol.InitLoggers()
defer gomol.ShutdownLoggers()

// Log some debug messages with message-level attrs
// that will be sent only with that message
for idx := 1; idx <= 10; idx++ {
	gomol.Dbgm(
		gomol.NewAttrs().
			SetAttr("msg_attr1", 4321),
		"Test message %v", idx)
}

Index

• Variables
• type GomolJsonError
  • func (gje *GomolJsonError) Error() string
  • func (gje *GomolJsonError) Temporary() bool
  • func (gje *GomolJsonError) Timeout() bool
• type JSONLogger
  • func NewJSONLogger(config *JSONLoggerConfig) (*JSONLogger, error)
  • func (l *JSONLogger) Healthy() bool
  • func (l *JSONLogger) InitLogger() error
  • func (l *JSONLogger) IsInitialized() bool
  • func (l *JSONLogger) Logm(timestamp time.Time, level gomol.LogLevel, attrs map[string]interface{}, ...) error
  • func (l *JSONLogger) SetBase(base *gomol.Base)
  • func (l *JSONLogger) ShutdownLogger() error
• type JSONLoggerConfig
  • func NewJSONLoggerConfig(hostURI string) *JSONLoggerConfig
• type LoggerOption
  • func WithDialTimeout(timeout time.Duration) LoggerOption

Examples

• Package

Variables

var (
	ErrDisconnected = newGomolJsonError("disconnected", false, false)
)

Types

type GomolJsonError

type GomolJsonError struct {
	// contains filtered or unexported fields
}

func (*GomolJsonError) Error

func (gje *GomolJsonError) Error() string

func (*GomolJsonError) Temporary

func (gje *GomolJsonError) Temporary() bool

func (*GomolJsonError) Timeout

func (gje *GomolJsonError) Timeout() bool

type JSONLogger

type JSONLogger struct {
	// contains filtered or unexported fields
}

JSONLogger is an instance of a JSON logger

func NewJSONLogger

func NewJSONLogger(config *JSONLoggerConfig) (*JSONLogger, error)

NewJSONLogger creates a new logger with the provided configuration

func (*JSONLogger) Healthy

func (l *JSONLogger) Healthy() bool

Healthy will return true if the logger is connected to the remote host

func (*JSONLogger) InitLogger

func (l *JSONLogger) InitLogger() error

InitLogger does any initialization the logger may need before being used

func (*JSONLogger) IsInitialized

func (l *JSONLogger) IsInitialized() bool

IsInitialized returns whether the logger has already been initialized or not

func (*JSONLogger) Logm

func (l *JSONLogger) Logm(timestamp time.Time, level gomol.LogLevel, attrs map[string]interface{}, msg string) error

Logm sends a JSON log message to the configured host

func (*JSONLogger) SetBase

func (l *JSONLogger) SetBase(base *gomol.Base)

SetBase will set the gomol.Base this logger is associated with

func (*JSONLogger) ShutdownLogger

func (l *JSONLogger) ShutdownLogger() error

ShutdownLogger shuts down the logger and frees any resources that may be used

type JSONLoggerConfig

type JSONLoggerConfig struct {

	// A URI for the host to connect to in the format: protocol://host:port. Ex: tcp://10.10.10.10:1234
	HostURI string

	// DialTimeout is the amount of time the logger will try to connect to the host before timing out
	DialTimeout time.Duration

	// The delimiter to use at the end of every message sent. Defaults to '\n'
	MessageDelimiter []byte

	// The prefix to add before every field name in the JSON data. Defaults to a blank string
	FieldPrefix string
	// A list of field names excluded from having the FieldPrefix added
	UnprefixedFields []string

	// The name of the JSON field to put the log level into. Defaults to "level"
	LogLevelField string
	// The name of the JSON field to put the message into. Defaults to "message"
	MessageField string
	// The name of the JSON field to put the timestamp into. Defaults to "timestamp"
	TimestampField string

	// A map to customize the values of each gomol.LogLevel in the JSON message.
	// Defaults to the string value of each gomol.LogLevel
	LogLevelMap map[gomol.LogLevel]interface{}

	// A map of additional attributes to be added to each JSON message sent. This is useful
	// if there fields to send only to a JSON receiver.  These will override any existing
	// attributes already set on a message.
	JSONAttrs map[string]interface{}

	// The number of messages to queue during a connection failure before
	// older messages will start being dropped. Defaults to 100
	FailureQueueLength int

	// Whether an active connection is required on initialization. Defaults to false.
	// If true, the Init function will return a nil error on connection failure, but
	// retry to connect in the background.
	AllowDisconnectedInit bool

	// The backoff strategy to use when reconnecting a connection
	ReconnectBackoff backoff.Backoff
	// contains filtered or unexported fields
}

JSONLoggerConfig is the configuration for a JSONLogger

func NewJSONLoggerConfig

func NewJSONLoggerConfig(hostURI string) *JSONLoggerConfig

NewJSONLoggerConfig creates a new configuration with default settings

type LoggerOption

type LoggerOption func(cfg *JSONLoggerConfig)

func WithDialTimeout

func WithDialTimeout(timeout time.Duration) LoggerOption

WithDialTimeout sets the amount of time the logger will try to connect to the host before timing out